Selector mechanism for printing telegraph receivers



Sept. 12, 1950 R. D. SALMON 2,521,750

SELECTOR MECHANISM FOR PRINTING TELEGRAPH RECEIVERS Filed Dec. 13, 19462 Sheets-Sheet l INVENTOR fPfG/NHZO 0. 5/71 MU/V ATTO R N EY Sept. 12,1950 R. D. SALMON 2,521,750

SELECTOR MECHANISM FOR PRINTING TELEGRAPH RECEIVERS Filed Dec. 13, 19462 Sheets-Sheet 2 ATTORNEY Patented Sept. 12, 1950.

SELECTOR MECHANISM FOR PRINTING TELEGRAPH m omvens 1 Reginald DennisSalmon, 'Croydon, England, assignor to Creed and Company Limited,'Croydon, England, a British company Application December 13, 1946,Serial No. 715,903 In Great Britain October 23, 1945 Section 1, PublicLaw 690, August 8, 194-6 Patent expires October 23, 1965 6 Claims. 1

This invention relates to printing telegraph receivers. Moreparticularly the invention relates to that kind of printing telegraphreceiver in which storage members are set in accordance with the codeelements of the signal combination and these members are afterwardscaused to act upon the translator mechanism. The present inventionrelates to the selecting and storage mechanism and is independent of thenature of the translator mechanism, that is, the mechanism fortranslating the setting of the storage members into the positioning of atype wheel, selection of a type bar or like means for ensuring that thecorrect character or representation thereof is printed or perforated.

It is the object of the present invention to provide a signal selectorand storage mechanism of simple construction that is cheap and easy tomanufacture and maintain and having a higher degree of tolerance thanknown mechanisms for distorted signals without increasing the powerconsumption. l

a The degree of tolerance for distorted signals dependsupon the timerequired for the current in the magnet winding to rise to its operatingvalue and the time required for the armature to move to its operativeposition. In order to reduce the last mentioned time it is one object ofthe present invention to reduce to a minimum the moment of inertia ofthe electromagnet armature system.

In one representative known arrangement described in British PatentSpecification #228,842, storage members are set by a striker pintraversed past them and struck towards successive storage members in themiddle of successive signal elements, the striker pin. being efiectiveto set the respective members in accordance with the position of-themagnet armature at the appropriate time. It was accordingly necessaryfor a member carried by the armature system to be sufiiciently extendedto cover five successive positions of the striker pin (for a -unitcode).

According to one feature of the present invention I provide a signalselector and storage mechanism for a printing telegraph receivercomprising storage members for the successive elements of abodecombination, means for traversing said storage members past the positionof a member carried by the armature of the receiving magnet, and meansfor setting successive storage members in accordance with the successivepositions of the armature.

' By means of this feature the armature memher-that acts upon thestoragemembers can be .made of extent only large enough to co-operate isthen struck in the last mentioned direction to act upon the successivestorage members.

On the other hand the said armature member may be carried in guides inthe armature system and be struck endways to act upon the successivestorage members.

Another factor affecting the tolerance of the signal selecting mechanismto distorted signals is the moment of inertia of the selector cam. Whenthe start element of a signal is received this cam must be acceleratedto the required angular velocity and the rate of acceleration will varyfrom time to time due to changes in the condition of its driving clutch.The moment of operation of each selecting action with respect to thestart element of the signal will vary. In order to reduce the magnitudeof this variation the time required to accelerate the cam must be madesmall. This involves either a powerful clutch or a low moment of inertiaof the cam.

The selector cam assembly therefore, is preferably driven by a clutchindependently of all other cams in the machine.

By this means the moment of inertia of the selector cam assembly is madevery small and can be made of very light and rigid construction.Preferably also the clutch driving the selector cam assembly is afriction clutch since this can be made'to have less Variation in pick-uptime than a-ratchet clutch.

Two embodiments of the invention are hereinafter described withreference to the accompanying drawings, in'which:

Figs. 1 to 6 show different parts of one form of signal selector andstorage mechanism according to the invention, th inter relation betweenthe parts being clear from the fact that at least one part is common toone or more of the figures.

Figs. '7 and 8 show a second form of signal selector and storagemechanism according to the invention.

Referrin to the drawings and first to Figs. 1

to 5, the signal receiving magnet l is shown in Fig. 1 somewhatdiagrammatically.

Whatever form of construction be used for this electrcmagnet I, theproportions and details of design are preferably such that it developsmaximum efiiciency for that particular degree of movement of thearmature "2 required to perform the operations described below.

The armature 2 is fixed to a pivot rod 3 mounted in fixed bearings (notshown). Fixed to the pivot rod 3 is a light armature lever 4. of thelever i is upturned at 5 and engages a latch 8 which is pivoted at i onone arm of a detent release lever 3 in the form of a bell crank, in turnpivoted at .l on the framework of the machine. The detent release leverB is urged in a counterclockwise direction by a spring i3, whilst thelatch 6 is urged in a clockwise direction by a spring I I.

The selector cam assembly consists of two discs only, one being a detentplate 12, Figs. 1 and 2, and the other the selector cam proper [3, Fig.3. These two discs are fixedly mounted on a short shaft I4, driven froma constantly rotating shaft (not shown) through a friction clutch inwell known manner. This cam assembly is very light and requires only asmall amount of power to accelerate it rapidly.

The selector cam assembly is normally held against rotation by means ofthe engagement of a projection 55 thereon with the bent over end of onearm l6, Fig. 1, of a detent lever. This detent lever has three arms Hi,I! and H3, and is pivoted at H! on a frame 28 that can be moved by handin an arc coaxial with the axis of rotation of the selector camassembly. Rotation of the frame is for the purpose of orientationadjustment, a scale 2i being provided to indicate the degree ofadjustment.

The middle arm ll of the detent lever embraces a pin 22 on the detentrelease lever-8. The third arm It is for the purpose of resetting thedetent lever in a manner presently to be explained.

When the start element of a signal is received the armature 2 moves tothe right in Fig. l zand rotates the armature lever L2 in aclockwisedirection, thus allowing the latch '6 to follow it and allowing thedetent release lever B to be moved by its spring it in acounterclockwise direction.

The arm l6 of the detent lever is-also rotated in 1 a counterclockwisedirection thus removing its end from the projection l5 and allowing these lector cam assembly to rotate in the direction of the arrow. Thelatch 6 is drawn by its spring El until it contacts with a fixedstop'23, which causes the latch ii to be disengaged from the upturnedend of the armature lever 4. I

The detent plate I2 is formed with two bent over lugs 24 and 25, lug 24being bent downwards from the plane of the paper in Fig. 1 and lug 255.."

being bent upwards. Lu 25, during the rotation 01" the detent plate l2engages the end of arm 18 0f the detent lever a little before the platehas returned to normal position. The detent lever is rotated clockwiseabout its pivot E9 the end of arm 16 replaced in the path of'projectionI5 on the detent plate and the selector cam. assembly is thus brought torest after one revolution. This will happen even if the armature 2remains in spacing position since the clockwise rotation of the detentlever it will cause rotation of lever 8 in a clockwise direction andupward movement of latch 8. Should the armature lever 4 be in'its lefthand position or marking position, latch 6 will re-engage the upturnedend 5 of armature lever 4, but if, due to non-receipt of the stopelement or other mischance, the armature l remains in spacing positionand armature lever 4 is in its right hand position, a, tooth 26 on thelatch ii will be moved beyond the fixed stop 23 and the spring One endI! will draw latch 6 to the right. Engagement of tooth 25 with the fixedstop 23 will then prevent movement of latch 6 downwards in Fig. l andthe detent lever B will be held with arm IS in engagement withprojection IS on the detent plate i2 and the selector cam assemblycannot be again released until the armature 2 has first been moved tomarking position, when the end 5 of armature lever will re-engage latch6, and then is moved to spacing position.

Lug 24 on detent plate l2 engages, shortly after the latter hascommenced its rotation, an arm of a. lever 21, Fig. 2, which is held bya spring 28 in engagement with a pawl 29 and thus holds the pawl 29 outof engagement with a ratchet 30. The ratchet 30 is mounted on a motordriven shaft 3,! and the pawl 29 is carried on a cam sleeve 32 whichcarries the translator cam and other cams for the operation of themachine, other than the selector cam assembly. When lug 24 on plate l2engages the lever 21, the latter is moved out of engagement with thepawl 29 and allows the latter to be drawn by spring (not shown) intoengagement with the ratchet 30.

U The pawl 23 and ratchet 30 constitute a well known form of ratchetclutch by means of which when engaged the cam sleeve 22 is driven by themotor driven shaft 21.

The left hand arm of the armature lever 4 carries at its end a plate 33,Fig. 3, having therein a slot in which slides one end of a striking rod34, the other end of which is pivoted to the end of a striking lever 35.This latter lever is pivoted at 36 and is drawn to the right in Fig. 3by a spring 31, with a roller 38 on the lever engaging the selector caml3. The selector cam I3 is formed with five humps which cause leftwardmovement of lever 35 and so move striker rod 34 to the left. It will beobserved that the left-hand end of armature 4 is provided with abent-over lip 33 which can assume either one of two positions, namelythe full-line position or the dotted line position shown in Fig. 3,depending upon whether the magnet I is energized or de-energized.Mounted adjacent the lip 33 is a pivoted lever 35a which is held in theposition shown in Fig. 3, against the tension of spring 36a and undercontrol of the lever 35 when the roller 38 is resting in a valley of thecam I3 as a result of the tension of spring 37. In this relation, thelever 35a has its lower end held in the position shown in Fig. 3 byengagement with a suitable groove or notch in rod 34. When the roller 88engages a raised portion of cam I3, the lever 35a is moved to the leftand if the armature 4 is in full line position as shown in Fig. 3, theright angled lip 31a of lever 35a latches over the upper surface of lip33, thus mechanically holding the armature in its full line position.If, however, the magnet is energized, the armature 4 moves the lip 33 tothe dotted position shown in Fig. 3, so that the movement of lever 35causes the lip 31a to latch beneath the lip 33, thus holding thearmature 4 in its operated position.

As previously described the translator cam sleeve 32, Fig. 2, has beenreleased for rotation. This cam sleeve carries cams to control thetranslating mechanism and to initiate other functions of the machine.One of the cams thereon, viz. cam 39, Fig. 3, causes the endwaystraverse of a frame 40, Figs. 3 to 6, along a spindle 4!. The frame 40carries a pin 42 the axis of which is parallel to spindle 4|. Mounted onpin 42 are five. signal storage members 43 separated from each other byspacing washers. The storage members 43 and washers are pressed togetherby a spring 44, Fig. 5, mounted on the pin 42. The storage members arefree for a limited amount of rotation on pin 42 being held by frictionin the position into which they are rotated whilst the washers areprevented from rotating with respect to the pin.

The shape of the storage members 43 is seen in Fig. 3 and in Fig. 6.Each of them is formed with short arms extending vertically upwards anddownwards respectively and a horizontal arm.

Endways motion of the frame 46 causes the storage members 43 to betraversed past the end of the striker rod 34, Fig. 3. When the armaturelever 4 is in its lowest position striker rod 34, when moved to the leftin Fig. 3, strikes the upper vertical arm of a storage member 43. Whenthe armature lever 4 is in its upper position, striker rod 34 misses thestorage member. The endways motion of the frame 40 is timed by cam 39 sothat the five storage members 43 are brought into line with the strikerrod 34 seriatim so that the successive storage members 43 are struck bysuccessive striking actions of the rod 34.

As the frame 40 moves endwise into the position when the fifth storagemember 43 can be struck by rod 34, a hole in the side of the frame 40engages a pin 45 fixed to a two-armed lever 46 fixed on the spindle 4|,Fig. 4. Lever 46 carries rollers 41 engaging cams 48 on the translatorcam sleeve. After the fifth striking action is completed one of the cams4B acting on lever 46 rocks the spindle 4| to move the storage members43 away from the striker rod 34 and towards five pairs of bell cranklevers 49. One pair of these levers is shown in Fig. 4.

The bell crank levers 49 are pivoted on pins 50 and 5| respectively. Thevertical arms of each pair extend towards one another and the horizontalarms extend in a direction away from the striker rod 34. The horizontalarms of each pair of bell crank levers 49 engage with a vertical rod 52which is linked with a combination disc 53, Fig. 4.

When a storage member 43 is in the unset po sition represented by thefull line in Fig. 4, it engages the downwardly extending arm 49a of itscorresponding upper bell crank lever 49, and when in the set positionrepresented by the dotted line in Fig. 4, the storage member 43 engagesthe vertical arm 49b of the lower bell crank lever. Actuation of theupper bell crank lever 49 will move the vertical rod 52 into an upperextreme position and actuation of the lower bell crank lever 49 willmove this rod into a lower position. Movement of the rod 52 will resultin rotation, in one direction or the other, of the correspondingcombination disc 53.

Immediately the storage members 43 are moved clear of the bell cranklevers 49 after the vertical rods 52 are set, the frame 40 is moved bycam 39, Fig. 3, endways to bring the first storage member 43 again intoline with the striker rod 34. During its sideways and rotary motion theframe 46 is controlled by a guide plate 54 (Figs. 4 to 6) and as theframe 46 returns to its initial position and becomes disengaged from thedriving pin 45, the frame is controlled in a fixed rotary position bythis guide plate. One of the cams 48, acting on lever 46 rotates thespindle 4| with the driving pin 45 disengaged and a resetting lever 55,Fig. 6, fixed to spindle 4| engages the downward projection on eachstorage member 43 and ture 2 has fixed thereto a blade 56 havingconsiderable rigidity in a plane at right angles to a plane containingthe axis of the spindle 3 but having compliance in a direction parallelto the axis of that spindle.

The selector cam assembly consists, as in the first embodiment describedof a detent plate and a selector disc l3. The arrangements for releasingthis cam assembly for rotation and for the release by the detent plateof the translator cam assembly are similar to those in the firstembodiment.

v The selector lever 35 is acted on by the selector cam l3 as previouslydescribed and strikes the blade 56 sideways towards a storage member 43.The storage members are of slightly different shape from those in thefirst embodiment and each has a vertical projection 43a. tocooperatewith theblade 5t and two other projections 43b and 430. Thestorage'members 43 are mounted in a frame 4|; and are traversed past theend of blade 56 by a cam 33 onthe translator cam sleeve. When selectorlever 35 strikes blade 56 sideways, the blade 56 either rotates astorage member 43 or misses it, according to the position of thearmature 2.

When the frame 46 has moved into the position where the fifth storagemember 43 can be struck and lever 35 has finished its stroke, a cam 31rotates a bell crank lever 58 in a clockwise direction against a spring59.

Pivoted on a common pivot 60 on bell crank lever 58 are five swordmembers 6| which are thus brought against the arms of theircorresponding storage members 43 and rotated according to the positionsin which said storage members were set. The sword members 6| are linkedwith combination discs '53 which are accordingly rotated through a smallarc in one direction or the other.

The swords 6| after being set are moved clear of the storage members 43and immediately afterwards the frame 46 is moved to bring the firststorage member again into line with the end of the selecting blade 56.

What is claimed is:

1. Signal selector and storage mechanism for a printing telegraphreceiving machine, comprising, an electro-magnet having an armature, aplurality of selectively shiftable storage elements, one for each signalelement of a plural element code, a setting member controlled by saidelectromagnet for setting said storage elements, said storage elementsbeing mounted in an array with respect to said member so that saidmember is capable of cooperative engagement with respect to only one ofsaid elements at a time, a frame carrying said storage elements, camcontrol means for reciprocating said frame laterally with respect tosaid setting member, and other cam control means for moving said framebodily as a unit in a direction transverse to said reciprocatingmovement for causing said setting member to be operative to set each ofsaid storage elements in turn in accordance with the selective positionsof said armature as determined by the successive code elements of areceived signal.

2. Signal selector and storage mechanism according to claim 1, furthercomprising a plurality of code combination discs, one for each elementof the code, a plurality of pairs of rockably mounted elements, eachpair linked to a difieren't one of said discs and the elements of eachpair adapted to move said discs in opposite directions, said storageelements mounted in selective positioning array with said pairs ofrockable elements, each of said storage elements adapted to engageeither of said rockable elements in response to movements of saidsetting member.

3. Signal selector and storage mechanism according to claim 1 in whichsaid storage elements are mounted in a reciprocating frame, cam controlmeans are provided for reciprocating said frame laterally with respectto said settingmember, means tomove said frame and said storage elementsin one direction perpendicular to said reciprocation movement, and meansto re-set said storage elements while said frame is being moved in theopposite direction perpendicular .to said reciprocation movement.

4. Signal selector and storage mechanism according to claim 1 in whicheach of said storage elements comprises, an operating arm arranged toassume either an upper or lower position as determined'by saidelectromagnet, a plurality of upper and lower sets ofbell crank levers ioperative engagement with said storage element arms,

and a plurality of shiftable combination rods arranged to be movedselectively in either direction under control of an associated one ofsaid bell crank levers.

5. Signal selector and storage mechanism according to claim 1 in whichcam control means are provided for locking said armature in either oftwo positions while said storage elements are being set by said settingmember.

6. Signal selector and storage mechanism according to claim 1 in whichsaid armature carries a locking lip and a locking lever is pivotallymounted with respect to said lip to lock the armature in either of itstwo selective positions while said storage elements are beingselectively set by said setting member.

REGINALD DENNIS SALMON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,108,529 Underhill Aug. 25, 19141,904,164 Morton et a1 Apr. 18, 1933 1,917,308 Krum July 11, 19331,932,932 Griffith Oct. 31, 1933 2,262,471 Shoenberg Nov. 11, 19412,273,083 Angel Feb. 17, 1942

